Method of and apparatus for forming flexible tubes



L. H. BRINKMAN.

METHOD OF AND APPARATUS FOR FORMING FLEXIBLE TUBES.

APPLICATION FILED APR. 12. 1918.

' Patented Mar. 21, 1922..

' 3 SHEETS-SHEET I.

INVENTOR ML- fiwn $1 ATTORNEY L H. BRINKMAN.

METHOD OF AND APPARATUS FOR FORMING FLEXIBLE TUBES.

APPLICATION FILED APR. 12. I918.

Patented Mar. 21, 1922.

3 SHEETS-SHEET 2.

w INVENTOR MTORNEY Alum num 76 f A Patented Mar. 21, 1922 3 $HEETSSHEET 3. 55 29 llllllll. unuuuuuu2n' L. H. BRINKMAN.

METHOD OF AND APPARATUS FOR FORMING FLEXIBLE TUBES.

APPLICATION FILED APR.12, 1918.

ar 'a 60 exam g E INVENTOR UNITED FISTATES PATENT OFFICE.

Louis E. BRIN'KMAN, or GLEN RIDGE, NEW JERSEY, ASSIGNOR 'ro rrrnrnnx KETAL HOSE CORPORATION, A CORPORATION OF NEW YORK.

METHOD OF AND APPARATUS FOR FORMING FLEXIBLE TUBES.

Specification of Letters-Patent.

Patented Mar. 21, 1922.

Original application filed November-'18, 1915, Serial No. 62,108. Divided and this application minim 12, 1918. Serial No. 228,117. H v

Glen Ridge, Essex County, State of ew Jersey, have invented new and useful Improvements in Methods of 'and Apparatus for Forming Flexible Tubes, of which the following is a specification.

This invention relates to methods and apparatus for formi tubes wherein a strip or ribbon is helical y disposed and the adj acent convolutions are secured together by the interfolding of adjacent edges of the convolutions.

flexible tubes of the character indicated wherein the ribbon or stri of which the tube is formed has al longitudinal groove, flexing of the tube being permittedby relative movement of the sides of the groove.

This application is a division of my prior application Serial Number 62,108, filed November 18th,*1915.

The main object of the invention is to provide methods and means for insuring a more reliable, solid and tight joint or seam between the convolutions of the strip or ribbon forming the tube.

Other and ancillary objects of the invention will appear hereinafter.

In the accompanying drawings which illustrate the invention of means and in connection with which the method is also illustrated, I

Figure l is-a side elevation of a machine embodying the invention of means and by which the method invention may be carried out, some of the extremities being omitted so as to bring the illustrationproperly within the compass of the sheet and which will be readily understood from the description, with some parts in section;

Fig. 2 is a section on a reduced scale through the frame and headstock spindles on the line 22 of Figure 1, looking in the direction of the arrow, the clutch and clutch shifting members being shown in elevation;

Fig. 3 is an end elevation on an enlarged scale, of the tube forming nut or die and its appurtenant apparatus;

Fig. 4 is a top plan view of the same;

Fig. 5 is an end view of the preliminary strip former feeding the strip into the forming threads of the die and screw, the view immediately involved in its formation, showing more clearly the details of construction of-the tube and of its formation by the die and screw;

Fig. 8 is a still further enlarged section of a fragment of one side of the tube as it emerges from the forming nut showing more More particularly the invention relates to' fied form of strip before being fed intfi the nut;

Fig. 12 is a longitudinal section of a fragment of a tube formed of a strip as shown in Fig. 11, as it emerges from the formingnut; 1 Fig. 13 isa view similar to'Fig. 12 showing that tube after the joints have been crimped and the groove walls have been reflexed by longitudinal compression; and

Fig. 14 is a sectional view of one of the pressure rollers for compressing and crimping the joint in conjunction with a section of a joint illustratin its operation thereon.

Referring to the rawings, the apparatus comprises a support or. frame A upon which is mounted a headstock comprising the rotatably mounted spindle B, the reversible driving mechanism 0 therefor and the chuck D. Within the chuck is secured a screw-rod E carrying a screw thread which co-operates with a longitudinally movable nut F to form the. tube. Also the screw rod has a thread engaging with a longitudinally moving nut G for appropriately reversing the direction of rotation of the rod.

Referring to the drawings more in detail. the spindle B of the headstock is supported in the bearings 1 and 2 and rotatably mounted upon it are the belt pulleys 3 and 4 upon which run the belts 5 and 6 driven in 0pposite directions by any suitable source or sources of wer. Splined upon the spindle is a movab e clutch member 7 which may be slid longitudinally to alternately engage the pulleys 3 "and 4. p

In order to shift the movable clutch memher to reverse the direction of rotation of the chuck and screw rod, and to securely hold it in the osition to which it may be moved, the clutcii member has extending laterally from it two trunnions 8 and 9 which are embraced by the forks 10 and 11 at the ends of a'yoke journalled in the frame.

The yoke comprises a sleeve 13 to the ends of which the arms 14 and 15 carrying the forks 10 and 11,. are fixed. The yoke is held in: position to cause driving engagement with'one of the pulleys 3 or 4 by an oil-center spring 16 having one end secured at 15 to an extension of the arm 14, and the other end to a suitable stationa point.

To move the yoke, He fixed upon a shaft 19which passes through and is rotatable in the sleeve 13. The arm 17 is provided with a disk 20 having a slot 21 which receives a pin 22 fixed to the ex tension of the .arm 14 of the oke. An 0ficenter spring 23 has one en connected to the arm 18 at 24 and has its other end secured to a fixed point. The pin 22 and slot 21 provide a connection which permits movement of the arms 17 and 18with relation to the yoke until the spring 23 has passed centre. The arms andyoke are then thrown together quickly into the position 'for reverse rotation, the springs 23 being stronger than the sprin 16. The spring 16 serves tohold the clutc in closed position during transition movements of the shifting mechanism. The arm 17 is moved in one direction orthe other by means of a link 25 which is pivoted to thearm at 25" and is connected with the nut G by a pin 26 and slot 27 The slot permits quick movement of the arm 17 after its spring has assed dead center. A similarly connected ink 28 extends between the arm 18 and the nut G upon the other side. Forward and backward movement of the nut G alon the rod E operates to throw the clutch mem er from one extreme to the other so that the direction of rotation of the spindle, chuck and screw rod is reversed at regular intervals for a purpose as will hereinafter appear.

The parts directly concerned in the for-- mation of the tubecomprise the nut F (30-01) crating with the threads 28 on the screw rod together with appurtenant appliances. The nut comprises a steel casing 29'having a central bore adapted to receive a steel die 30 and a brass bushing 31 closely fitting against it, the die and bushing being held in position and prevented from movement with relation to the casing by means or set armsl7 and 18 are.

this flange is such as to allow the passage of the tube as formed by the die and screw.

The bushing 3l 'may be threadedto receive the rotating screw threads with a running clearance as shown, and the steel die may have certain of its threads non-forming, as 35, 36, 37, etc., and it carries specially formed threads 38, 39 and 40 adapted to form the strip into the tube. After the tube forming threads have been passed the die has an unthreaded interior surface. To ermit the strip of which the tube is forms to be fed into the diefrom the side, the casing 29 and the die have segments cut away as 'shown particularly in Figs. 3 and 4, forming a recess having side walls 41 and 42 and an end wall 43. Secured to the wall 42 of the recess is a channel or former 45' for preliminarily shaping the ribbon prior to its introduction into the die. This former is flat at one end where it receives the flat ribbon 44 and at its other end is shaped as shown in Fig. 5. It will be observed that this former initiates a longitudinal groove 45in the strip and one edge is curled over shown at46. The ribbon passes fromjthe former 45 into the die, the bottom portion of the groove being between the top of the die thread 40 and the screw at the base of the screw threads. The sides 47 and 48 ex-' tend up on both sides of the die thread 40.

70 die abuts. The diameter of the bore inside" The side 48 has its extremity 50 bent to one 7 side in a channel cut in the die at the base of the thread. This channelis chambered offat 51, at the beginning, to facilitate the entrance of the strip, but soon merges, into the slot which is radial of the tube and. contains the flange 53. The width of this shit is such as to be substantially equal to the thickness of the edge of the ribbon or strip of which the tube is formed. Similar clearances are formed between the screw and the die at the base of the die thread and also about the die thread 40 except that at the outer face of the die thread the clearance is are made larger and the-adjacent ends of the and a; for the t I this locatnj" rances at the sides of the thread are screw threads.

curled over portion received. from the preliminary former is more sharply bent on entering the channel and consequently its tendency is to spring against the sides of the,

channel, leaving a clearance for one thickness of the ribbon between the sides of the bent over portion. Within this clearance is entered the radial-edge 53 of the precedingdie thread 4.0 about the screw, except that the channel 52 is narrowed as it progresses about the screw so that the bent over edge of the stri and its embraced edge of the next convo ution are pressed more closely together as shown at 54. The strip then emerges from the die into the recess andreenters the die about the die thread 39. The right hand side (as viewed in Figs. 6 and 7) is now embraced by the curled over portion of the edge of the succeeding convolution and its left hand edge, interfolded with the preceding convolution, will enter within the channel 56 cut in the die at the thread base. This channel-is formed at its beginning of a section as shown at 56 with an inclined wall which bends over the interfoldedv edges to one side. This section is gradually merged into the section as shown at 57 as it progreses about the die until the interlocked portions are-bent'down and occupy the position as shown at 57 the clearance between the die and thread being substantiall equal to four thicknesses of the ribbon. n this condition the; joined edges of the strip emerge from the die into the recess and are entered into a similarly shaped clearance 58 of similar depth between the die and The joint may be then passed around the screw one or more times without changing form and the, tube emerges from the nut having its sides of the groove in the strip substantially radial of the tube, the bottom of the groove upon the inside of the tube and the interfolded contiguons edges of the strip at the outside of the groove, the section of the tube being then as shown at 59 and exterior elevation as at 59'.' The tube then passes on between the grooved rollers 60 and 61 which bear upon.

the joint.

These rollers each have a groove 103 receiving the interfolded joint. This groove is of wedge shaped section so that when the rollers are forced. against the tube-the joint is compressed longitudinally of the tube,'thereby crimping the interfolded parts.

compacting and securing the. joint. 'Theform of thegroove relation to the joint is clearly shown in Fig. 14. It will be observed the groove is'so deep-that there is always a clearance between its bottom and her. as before referred to.

the joint to accommodate it radially as it is compressed longitudinally. It will be observed that the rollers are set in -a plane which makes an angle with the longitudinal axis of the tube corresponding to the helical pitch of the strip so that the rollers are The rollers may conveniently be rotatably mounted upon arms 62 and 63 pivoted to the end of the casing of the nut at 64 and 65. These arms are engaged by the ends of a spring 66 which tends to throw them away from the tube, the spring being secured to the end of the nut casing at its center 67. The rollers are forced against the tube by means of a screw 68 tapped into the tail 69 bviously by'turning this screw in one directionor the other the pressure of the rollers upon the tube may be made any'that is desired. A lock nut 71 on the screw provides for securing the arms and rollers in adjusted position. As the rollers bear against opposite sides of the tube they have no tendency to bend it to one side or the other.

The nut F as described, is secured to the stand or support 72 sliding upon the frame. This may be done by means of machine screw 73 passing through the head 74 and tapped into the nut casing, the casing being tappgd 4;

for this purpose at 75, 76, etc. The hea has a central opening to permit the passage of the screw E. It will be'observed that between the rollers and the end of the .die threads there are several convolutions of the thread onthe screw which'have no corresponding threads on the die or nut casof thescrew, however, causes the nut F to travel along adapted to the helical form of the joint.

of one of the arms 62 andbearin against the tail 70 of theother arm 63.

the screw member, and unless the tube 900- tions to be formed were very short, the apparatus would have to be-very long to accommodate the travel of the nut. For this reason provision is made ,for returning the nut to its starting pointfat suitabl intervals. This is the objectofjreversing the direction of rotation of the screw mem- In the. case shown theforming thread on the screw member is aright hand thread, as is also the thread 80 for the nut G. As, therefore, the screw, member is rotated in a clockwise direction,-

viewed from the headstock, the strip will be drawn in and the tube formed as described, the forming nut moving toward the headstock and the shifting nut G-movtirety may now be traced.

', The endof the strip is entered in the form 45' in which it has a groove initiated and one edge curledover as described;

From the former it is entered within the die or nut at the first forming thread as described and, the screw being turned, the strip is assed through the forming threads of the ie and on about the screw under the grooved rollers 60 and 61. As it enters the rollers it is of a longitudinal section as shown at 59. In passing under the rollers, the joint is crimped as before explained, the" section then being shown at 100'. In

. passing through the forming channels, it will be observed that the clearances are such ast'o force the-interfolded edges tightlytogether and the folding of one bends so that a fixed tight joint is formed. The form as shown in section at 59 may be 'the'final form, and for some purposes may be passed through forming channels of the'die and further that the apparatus is in the best, but the joint may be crimped and the 1 tube com res'sed or refiexed later into a form, section of which is shown at 95. The exterior view of the tube is shown at 97. Let it be assumed that the strip has been phase of operation as indicated in Fig. 1. In this position the apparatus has just completed a tube forming period, the nut G is substantiall at the extremity of its left hand movement see Fig. 1) and the forming nut F is substantially at the left hand extremity of its movement. The driving clutch has been thrown to the leftinto engagement with the pulley 3 so thatthe belt 5 driving the pulley in a counter clockwise direction, viewed from the left hand end, turns the screw rod in a similar direction. This will result in the withdrawal of the screw from the nut and from the tube or strip, the latter being backed ofi sufliciently to release'the torsional gripping between. it and the screw. The nut F then moves toward the right carrying with it the strip and tube, there bemg no turning of thelatter in this movement. During this operation, the shifting nut G is also carried to the right. At a certain point in its travel, depending upon the adjustment, the clutch member operating levers are moved past' center and the clutch member is thrown to the right into I engagement with the pulley 4. It will be apparent that the arrangement of levers-and off-center springs is such that the shifting of i the clutch is brought about practically in stantaneously so that there is no material discontinuance of the operation. The pulley 4, revolving in the opposite directlon from part about the other draws them tightly together at the that of the pulley 3', the direction of rotation of the screw will now be reversed.- As the screw thus turns,the strip-will beheld to it a by a torsional frictional grip sothat it turns- I with the screw, the sufficiency of this frictional grip being insured by the extra turns of the strip about the screw in addition to andinterfolds the edges of adjacent convolu- 1 tions, forcing these edges tightly together so that a fixed and fluidtight joint is formed. The tube then] asses on under the rollers 60 and 61 as be ore described. During this operation it being observed that .the screw does notmove' longitudinally, the forming nut moves to the left Fig h1) the screw and strip turning within it. is is kept up as long as thescrew is turned in the direction indicated.

During the left hand travel of the forming nut the shifting fnut G is carried to the left until, at a certain predetermined point, the driving clutch is again shifted to the position shown in the drawings. The parts of the machine will then occupy-positions as shown in Fig. 1 and a cycle of'operation has been completed and may be repeated indefinitely as long as may be desired to operate the machine.

The tube, of section as shown at 59, as it is delivered by the forming nut and screw may, as before stated, be used as it is, but

it is desirable that it be compressed axially for instance, by passing a'rod through it, the rod having nuts at the ends of the tube. Pressure is then brought to bear on the ends of the tube by turning the nuts and the tube may thus be compressed longitudinally.

The grooved walls may thus be reflexed and the tube formed to have a longitudinal section as shown at 95 and an. exterior as an elastictransversely tapering layer 100' of spring steel. It will be observed that the center line of the steel layer is at one side of the "center lineof the strip. This is for the reason, as clearly illustrated in Figs.

8' and 9, that a greater width'of one edge of the strip is used up in making the interfolded joints-than is consumed for this purpose at the other edge of the strip. It will be seen that in this particular construction the steel layer does not enter into the interfolded joints but provides a reinforcement which supplies elasticity in the groove walls.

-with which it has been illustrated.

The tube is less liable therefore to develop a set when it is flexed but returns to its initial condition, also opposes a greater resistance to elongation under pressure, and is stronger. Inasmuch as the steel does not enter into the interfolds they are more easily made of the more easily workable brass. which. will take and hold the desired set to produce relative immovability of the interfolded parts and insure tightness of the joint. Further the brass will protect the steel from the corrosive action of many fluids which might be conducted through tube. The transverse tapering of the strip from the center towards its edges gives a desirable distribution of elasticity and also distributes the bending moment properly along the walls of the groove.

Fig. 11 shows a modified form of strip comprising two layers, it being similar to the strip shown in Fig. 10 except that the bottom layer 'is removed, the modified form of strip having the layer 101 and the transversely tapering layer 102 of suitable spring metal. Where the tube is used to convey Y fluids having corrosive action on steel, this layer is preferably made-of spring brass. In forming the tube this strip is fed lnto the apparatus with the spring metal layer lowermost so that the spring metal is upon the inside and the other layer upon the outside of the tube so that the spring metal may efiiciently act to prevent elongation, and at the same time acting to prevent set of the tube under flexure.

While the invention of apparatus has been illustrated in what is considered its best application and the invention of method has been illustrated in connection therewith, the

invention of apparatus may have other embodiments without departing from its spirit, and is not therefore, limited to the structure shown in the drawings; nor is the method limited to' the precise details recited nor to practice with the apparatus in connection What I claim is 1. The method of forming a tube from a strip which consists in helically dlsposing the strip, interfolding the edges of ad'acent convolutions and exerting oppositely irected pressures longitudinally of the tube upon opposite sides of the seam formed by the interfolded portions to crimp the same.

4. The method of forming a flexible tube from a strip which consists in forming a longitudinal groove therein, helictlly disposing the strip, interfolding the edges of adjacent convolutions and exerting oppositely directed pressures longitudinally of the tube upon opposite sides of the seam formed by the interfolded portions to crimp the same.

5. In an apparatus for forming a tube from a strip, the combination with means for helically forming the strip, means for interfolding the edges of adjacent convolutions and means for crimping the interfolded portions.

6. In an apparatus for forming a tube from a strip, the combination with means for helically forming the strip, of means for forming a longitudinal groove. in the strip, means for interfolding the edges of adjacent convolutions and means for crimping the interfolded portions.

7. Means for crimping the seam. of a tube formed from a helical strip comprising in combination means for supporting the tube, a member having a wedge shaped channel adapted to receive the seam and compress the same longitudinally of the tube as said memher is pressed toward the tube, means for pressing the said member against the said seam and means for relatively rotating the tube. and member.

8. Means for crimping the seam of a tube formed from a helical strip comprising in combination means for sup-porting the tube, a roller having a wedge shaped groove adapted to receive the seam and compress the same longitudinally of the tube as the roller is pressed toward the tube, means for pressing theroller against the seam and means for rotating the tube. v

9. In an apparatus for forming a flexible tube from a strip, the combination of forming members consisting of a nut and a 00- operating screw having clearances between them to receive said strip and one of said members having bending channels adapted to receive the edges of the strip and interfold the same, means for rotating the screw with relation to the nut, grooved rollers bearing upon the seam of the tube as it issues from the nut and is rotated by the screw, and means for pressing said rollers inwardly against the tube, the grooves in said rollers being adapted to receive the interfolded portions and to compress the same longitudinally of-the tube as they are pressed inwardly.

In testimony whereof I have signed this specification this 11th da of April, 1918.

LOUIS BRINKMAN. 

